WPC Gwen Cooper is at the scene of a brutal murder, when the "special ops," known only as Torchwood, arrive. After witnessing the group bring the dead man back to life, Gwen goes in pursuit of this mysterious organisation, only to see weirder things than she could ever imagine existed. Soon after, she begins to regret giving in to her curiosity, when she meets Captain Jack Harkness.

It's Gwen's first day on the job, and it's not going very well. After accidentally releasing a mysterious gas from a comet that landed, a new type of alien is let loose on the streets - an alien that's addicted to sex. Torchwood must find the inhabited body, and prevent anymore deaths from the violent form of sex.

Whilst chasing a man, Gwen retrieves an unusual machine that allows the user to see back into the past. It is considered dangerous, and no members of Torchwood are permitted to use it. But Owen has other plans, and witnesses a violent murder that took place over forty years ago. Using the information he gathered, Owen starts to track down the still-living murderer.

A Ianto themed episode Ianto Jones hides a very big secret at Torchwood - his half-converted girlfriend from the Canary Wharf Battle - down in the basement. He is quick to hire a Japanese doctor who believes he can "cure" her. But things soon go wrong, and the Cyberwoman's destructive powers are released to the whole of Torchwood. Upgrading is compulsary.

Jack catches up with a very old friend of his, who is investigating fairy sightings in the local wood. After having visited her, Torchwood are informed of a man's mysterious death in a prison cell. Then, Tosh uncovers a series of localised, extreme weather patterns. Nobody at the organisation is sure of these events, or how they may be connected. Except Jack, who has witnessed the creatures causing this, almost a century ago.

Whilst investigating a group of unexplainable deaths in a village, the Torchwood team are separated. Discovering further, Jack, Gwen and Owen find a scared man, hiding from the thing responsible for the murders. But Tosh and Ianto go that one step extra, and locate the killer, who wants them as their next victims.